This invention relates to the fixing equipment or devices for flexible sheet. For example, in using the invention devices for attaching sheets on the frame of a plastic greenhouse, the securing of, the plastic films on the frame is made much easier and can be effected in one securing action. Furthermore, the devices can be used for cottage windows to fix both plastic films and mosquito nets, in a quick way and at low cost.
Generally, in a plastic greenhouse, or any type of a pipe house, large steel frame house or connected house, it is usual to stretch transparent plastic sheets over the roof and sides so that solar heat may be absorbed into the house through the plastic sheets.
However, the work of stretching the above mentioned plastic sheets on the roof framework or side framework of a greenhouse is very difficult. In fact, in fixing the sheets by using wires, pressing straps and nails, a great deal of labor and time are required and th working efficiency is very low. Furthermore, as the duration of plastic sheets is for two years at the most, such stretching work must be repeated every two years. In addition to the above mentioned fastening elements, many tools are required to use these elements. Consequently, it is expensive to stretch and secure plastic sheets over the framework of a greenhouse, for example.
A first object of the present invention is to obviate the above-mentioned problems so that users may easily stretch and fix plastic sheets on the framework of houses.
A second object of the present invention is not only easily to stretch and fix plastic sheets but also to very stably stretch and tension the sheets so that they will not loosen.
A third object of the present invention is to prevent stretched and fixed sheets from breaking.
A fourth object of the present invention is to prevent even rather hard sheets, fixed to a skeleton framework, from wrinkling.
A fifth object of the present invention is to provide devices for fixing sheets over a framework with few tools.
Another object of the present invention is to make the sheets perform the function of reinforcements for a skeleton framework.
A further object of the present invention is to provide devices for stretching and fixing mosquito nets and screen door frames and for stretching metal screens.
For an understanding of the present invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.